Shedding light on dark DNA Most textbook definitions of evolution state that it occurs in two stages: mutation followed by natural selection. DNA mutation is a common and continuous process, and occurs completely at random.
The average adult only eats 15 grams of fiber per day. Women need 25 grams of fiber per day, and men need 38 grams per day, according to the Institute of Medicine.
Fiber Needs. For adults aged 14 to 50, the adequate intake for fiber is 25 grams daily for women and 38 grams daily for men. This is about 14 grams of fiber per 1,000 calories. For adults older than 50, women need 21 grams per day and men need 30 grams daily. Very high fiber intake, more than 60 grams, creates health risks.